{"id":2918,"date":"2018-02-09T20:18:24","date_gmt":"2018-02-09T19:18:24","guid":{"rendered":"http:\/\/www.crowave.com\/blog\/?p=2918"},"modified":"2018-02-09T20:18:24","modified_gmt":"2018-02-09T19:18:24","slug":"av-metar-dvm-300-sa-ca3161-i-ca3162","status":"publish","type":"post","link":"https:\/\/www.crowave.com\/blog\/2018\/02\/09\/av-metar-dvm-300-sa-ca3161-i-ca3162\/","title":{"rendered":"AV metar DVM 300 sa CA3161 i CA3162"},"content":{"rendered":"<p>Danas je nabavljen digitalni voltmetar i ampermetar kojeg je izradio radio amater YU2RWE i dao mu oznaku DVM 300.<\/p>\n<p><a href=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140553.jpg\" rel=\"lightbox[2918]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-2919\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140553-1024x1009.jpg\" alt=\"P1140553\" width=\"1024\" height=\"1009\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140553-1024x1009.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140553-300x296.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140553-768x757.jpg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/p>\n<p>Kod ovog projekta iz samogradnje prvo se uo\u010dava odli\u010dno tvorni\u010dko metalno ku\u0107i\u0161te dizajnirano za ugradnju elektroni\u010dkih mjernih instrumenata koje daje vrlo profesionalan kona\u010dan izgled izgra\u0111enog sklopa. Za natpise su kori\u0161teni preslika\u010di (letraset), ugradnja vanjskih kontrola estetski je lijepo odra\u0111ena te instrument na prvi pogled izgleda kao da je tvorni\u010dke izrade.<\/p>\n<p><a href=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140567.jpg\" rel=\"lightbox[2918]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-2920\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140567-1024x738.jpg\" alt=\"P1140567\" width=\"1024\" height=\"738\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140567-1024x738.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140567-300x216.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140567-768x553.jpg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/p>\n<p>Unutra\u0161njost instrumenta na prvi pogled izgleda komplicirano, no zapravo se radi o vrlo jednostavnom sklopu koji se sastoji od:<\/p>\n<ul>\n<li>mre\u017enog transformatora sa osigura\u010dm, ispravlja\u010dem i stabilizatorom napona<\/li>\n<li>elektroni\u010dkog sklopa za A\/D konverziju i BCD dekoderom za 7-segmentni LED pokaziva\u010d<\/li>\n<li>plo\u010dicom sa otpornicima za naponski djelitelj za voltmetar<\/li>\n<li>plo\u010dicom sa otpornicima (shuntovima) za ampermetar<\/li>\n<\/ul>\n<p><a href=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140572.jpg\" rel=\"lightbox[2918]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-2921\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140572-1024x909.jpg\" alt=\"P1140572\" width=\"1024\" height=\"909\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140572-1024x909.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140572-300x266.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140572-768x682.jpg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/p>\n<p><a href=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140573.jpg\" rel=\"lightbox[2918]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-2922\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140573-962x1024.jpg\" alt=\"P1140573\" width=\"962\" height=\"1024\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140573-962x1024.jpg 962w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140573-282x300.jpg 282w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140573-768x818.jpg 768w\" sizes=\"auto, (max-width: 962px) 100vw, 962px\" \/><\/a><\/p>\n<p><a href=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140585.jpg\" rel=\"lightbox[2918]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-2924\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140585-895x1024.jpg\" alt=\"P1140585\" width=\"895\" height=\"1024\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140585-895x1024.jpg 895w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140585-262x300.jpg 262w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140585-768x879.jpg 768w\" sizes=\"auto, (max-width: 895px) 100vw, 895px\" \/><\/a><\/p>\n<p><a href=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140604.jpg\" rel=\"lightbox[2918]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-2925\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140604-1024x895.jpg\" alt=\"P1140604\" width=\"1024\" height=\"895\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140604-1024x895.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140604-300x262.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140604-768x671.jpg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/p>\n<p>Bolji pogled na mre\u017eni transformator sa ispravlja\u010dem i stabilizatorom napona. U stabilizatoru napona upotrijebljen je integrirani stabilizator 7810 koji daje stabiliziran napon od 10 V. Za elektroni\u010dki sklop voltmetra potreban je napon od 5 V te on ima vlastiti stabilizator 7805. Ova dvostruka konverzija napona napravljena je vjerojatno zbog prevelikog napona nabavljenog transformatora, no to \u0107emo provjeriti kad se upustimo u testiranje rada ovog instrumenta.<\/p>\n<p><a href=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140582.jpg\" rel=\"lightbox[2918]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-2923\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140582-1024x612.jpg\" alt=\"P1140582\" width=\"1024\" height=\"612\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140582-1024x612.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140582-300x179.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140582-768x459.jpg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140633.jpg\" rel=\"lightbox[2918]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-2928\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140633-1024x525.jpg\" alt=\"P1140633\" width=\"1024\" height=\"525\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140633-1024x525.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140633-300x154.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140633-768x394.jpg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/p>\n<p>Elektroni\u010dki sklop voltmetra bazira se na samo dva integrirana kruga uz minimalni broj vanjskih komponenti. To su integrirani krug CA3162 koji slu\u017ei za konverziju ulaznog analognog napona u digitalni signal, odnosno binarno kodirani decimalni broj (BCD) i integrirani krug CA3161 koji taj BCD kod dekodira za numeri\u010dki prikaz na tri 7-segmentna LED pokaziva\u010da. LED pokaziva\u010di su sa zajedni\u010dki povezanom anodom i napajaju se svaki preko svojeg tranzistora kako bi se osigurala dovoljna svjetlina. Navedena dva integrirana kruga prvenstveno su razvijena da budu me\u0111usobno kompatibilna i \u010dine gotov sustav za digitalna o\u010ditanja napona te se ova kombinacija \u010desto susre\u0107e u takvim sklopovima.<\/p>\n<p><a href=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140627.jpg\" rel=\"lightbox[2918]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-2927\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140627-1024x775.jpg\" alt=\"P1140627\" width=\"1024\" height=\"775\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140627-1024x775.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140627-300x227.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140627-768x581.jpg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/p>\n<p>Sa izravno dovedenim naponom na integrirani krug CA3162 ovakav voltmetar sa tri znamenke mo\u017ee pokazati maksimalno o\u010ditanje od 999 mV, odnosno -99 mV za spojeni negativni polaritet. Odgovaraju\u0107im predotporima, odnosno djeliteljima napona pro\u0161iruje se mjerni opseg voltmetra.<\/p>\n<p>Voltmetar se napaja naponom od 5 V i ima samo dva pode\u0161avanja: potenciometrom od 47 k\u2126 podesi se pokazivanje &#8220;nule&#8221; (sa kratko spojenim ispitnim kablovima), a sa potenciometrom od 10 k\u2126 vr\u0161i se kalibracija napona tako da se dovede neki poznati napon na ulazne stezaljke nakon \u010dega se pokaziva\u010d podesi na pokazivanje tu vrijednost napona.<\/p>\n<p><a href=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140649.jpg\" rel=\"lightbox[2918]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-2929\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140649-1024x793.jpg\" alt=\"P1140649\" width=\"1024\" height=\"793\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140649-1024x793.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140649-300x232.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140649-768x595.jpg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/p>\n<p>Bolji pogled na plo\u010dice sa mjernim otpornicima. Otpornici otporni\u010dkog djelitelja za voltmetar smje\u0161teni su na gornjoj plo\u010dici, otpornici za kalibraciju ampermetra na donjoj.<\/p>\n<p><a href=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140654.jpg\" rel=\"lightbox[2918]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-2930\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140654-1024x668.jpg\" alt=\"P1140654\" width=\"1024\" height=\"668\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140654-1024x668.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140654-300x196.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140654-768x501.jpg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/p>\n<p>Da bi voltmetar mjerio ja\u010dinu struje potrebno je paralelno mjernim stezaljkama ugraditi shunt, odnosno otpornik malog otpora na kojem se zatim mjeri pad napona koji je proporcionalan struji koja te\u010de kroz njega. Dakle i kod mjerenja struje instrument zapravo opet radi kao voltmetar. Na\u0161 instrument ima strujni mjerni opseg do 1 A za \u0161to je potreban shunt otpora 1 \u2126 i mjerni opseg do 10 A za \u0161to je potreban shunt otpora 0,1 \u2126. Shunt otpornici trebaju biti snage barem 5 W.<\/p>\n<p>Shuntovi su lemljeni izravno na stezaljke, jednako kao i potenciometar za kalibraciju ampermetra.<\/p>\n<p><a href=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140606.jpg\" rel=\"lightbox[2918]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-2926\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140606-1024x458.jpg\" alt=\"P1140606\" width=\"1024\" height=\"458\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140606-1024x458.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140606-300x134.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140606-768x343.jpg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/p>\n<p>Prebacivanje naponskih djelitelja, shuntova, kontrolnih LED i decimalne to\u010dke 7-segmentnog pokaziva\u010da povezano je preko kombinaciji sklopki a uz to su i stezaljke za mjerenje napona i struje odvojene. Osnovni sklop voltmetra je srce ovog instrumenta, a svi dodaci koji uklju\u010duju mjerne opsege i mjerenje struje zapravo su samo prilagodbe ulaza u osnovni sklop.<\/p>\n<p>Tako se na ulaz mo\u017ee dodati i neki temperaturni senzor, odnosno bilo koji drugi senzor sa analognim naponskim izlazom, mo\u017ee se dodatni i posebni baterijski krug za mjerenje otpora, opsezi se mogu pro\u0161irivati po \u017eelji, u kona\u010dnici, kao i kod svakog univerzalnog instrumenta, na kraju ulaznog kruga dobije se neki napon \u010dija veli\u010dina je proporcionalna veli\u010dini koju mjerimo. Dakle, \u0161to god mjerili to se mora na neki na\u010din pretvoriti u napon. Za struju koristimo shuntove s kojih skidamo napon, za mjerenje otpora koristimo pomo\u0107ne strujne krugove gdje opet mjerimo pad napona na otporniku, za sva druga mjerenja imamo senzore koji pretvaraju to \u0161to mjerimo u napon (tempetaruru, svjetlost, vlagu, tlak, ja\u010dinu zvuka itd.). Sve se svodi na napon, odnosno na voltmetar \ud83d\ude42<\/p>\n<p><a href=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140662.jpg\" rel=\"lightbox[2918]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-2931\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140662-1024x493.jpg\" alt=\"P1140662\" width=\"1024\" height=\"493\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140662-1024x493.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140662-300x144.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140662-768x370.jpg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/p>\n<p>Uz dana\u0161nju ponudu i cijene digitalnih multimetara vjerojatno nitko ne\u0107e za razonodu odabrati izradu jednog ovakvog instrumenta. No poku\u0161ajmo zamisliti neku elektroni\u010dku radionicu i tamo na polici jedan do drugoga ovaj instrument iz samogradnje i neki moderni jeftini digitalni multimetar. Koji \u0107e od njih dva privu\u0107i ve\u0107u pozornost? \ud83d\ude42<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Danas je nabavljen digitalni voltmetar i ampermetar kojeg je izradio radio amater YU2RWE i dao mu oznaku DVM 300. Kod ovog projekta iz samogradnje prvo se uo\u010dava odli\u010dno tvorni\u010dko metalno ku\u0107i\u0161te dizajnirano za ugradnju elektroni\u010dkih mjernih instrumenata koje daje vrlo profesionalan kona\u010dan izgled izgra\u0111enog sklopa. Za natpise su kori\u0161teni preslika\u010di (letraset), ugradnja vanjskih kontrola estetski [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":2931,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[15,54],"tags":[],"class_list":{"0":"post-2918","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-mjerni","8":"category-samogradnja","9":"czr-hentry"},"jetpack_featured_media_url":"https:\/\/crowave.com\/blog\/wp-content\/uploads\/2018\/02\/P1140662.jpg","_links":{"self":[{"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/posts\/2918","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/comments?post=2918"}],"version-history":[{"count":2,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/posts\/2918\/revisions"}],"predecessor-version":[{"id":4774,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/posts\/2918\/revisions\/4774"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/media\/2931"}],"wp:attachment":[{"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/media?parent=2918"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/categories?post=2918"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/tags?post=2918"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}